YES

3 decompositions
 #1 -----------
   1: F(x1,x2) -> c(A())

 #2 -----------
   2: G(x3) -> x3

 #3 -----------
   3: h(x4) -> c(x4)

@Knuth and Bendix' criterion
--- R
   1: F(x1,x2) -> c(A())

--- S
   1: F(x1,x2) -> c(A())


@Knuth and Bendix' criterion
--- R
   2: G(x3) -> x3

--- S
   2: G(x3) -> x3


@Knuth and Bendix' criterion
--- R
   3: h(x4) -> c(x4)

--- S
   3: h(x4) -> c(x4)